Search

SUMMARY In the field, necrosis area induced by pathogens is usually surrounded by a red circle in apple fruits. However, the underlying molecular mechanism of this phenomenon remains unclear. In this study, we demonstrated that accumulated salicylic acid (SA) induced by fungal infection promoted anthocyanin biosynthesis through MdNPR1‐MdTGA2.2 module in apple (Malus domestica). Inoculating apple fruits with Valsa mali or Botryosphaeria dothidea induced a red circle surrounding the necrosis area, which mimicked the phenotype observed in the field. The red circle accumulated a high level of anthocyanins, which was positively correlated with SA accumulation stimulated by fungal invasion. Further analysis showed that SA promoted anthocyanin biosynthesis in a dose‐dependent manner in both apple calli and fruits. We next demonstrated that MdNPR1, a master regulator of SA signaling, positively regulated anthocyanin biosynthesis in both apple and Arabidopsis. Moreover, MdNPR1 functioned as a co‐activator to interact with and enhance the transactivation activity of MdTGA2.2, which could directly bind to the promoters of anthocyanin biosynthetic and regulatory genes to promote their transcription. Suppressing expression of either MdNPR1 or MdTGA2.2 inhibited coloration of apple fruits, while overexpressing either of them significantly promoted fruit coloration. Finally, we revealed that silencing either MdNPR1 or MdTGA2.2 in apple fruits repressed SA‐induced fruit coloration. Therefore, our data determined that fungal‐induced SA promoted anthocyanin biosynthesis through MdNPR1‐MdTGA2.2 module, resulting in a red circle surrounding the necrosis area in apple fruits. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Regulating spin crossover (SCO) behavior, especially controlling the spin transition steps, is an important scientific issue, mainly because people aim to control spin bistability and multistability. Presently, SCO bistability can be regulated by changing the ligand‐modifying species, non‐coordinated anions, guest molecules, and metal‐ion dopant. However, the control of multistability is extremely challenging, especially in Fe(III) SCO compounds. Here, we report that [FeIII(H‐5‐Br‐thsa)(5‐Br‐thsa)]·H2O (5‐Br‐thsa = (5‐bromo‐2‐hydroxybenzylidene)hydrazinecarbothioamide), a compound we have reported before, exists in two polymorphic forms: polymorph 1 exhibits three‐step SCO, and polymorph 2 shows five‐step SCO, with multi‐step SCO behavior effectively regulated by polymorphism. According to single‐crystal and powder X‐ray diffractometry, polymorphs 1 and 2 crystallize in different space groups during their spin transitions, with two‐step symmetry breaking observed (Pbcn → Pnc2 → Pbcn for polymorph 1; P21/n → Pn → P21/n for polymorph 2). We realized that the behavior of these two polymorphs depends significantly on the structure, including (i) the average Fe—N bond distance, (ii) deformation of octahedral FeIII atoms, and (iii) distinct crystal packing, which account for the large differences observed in magnetic properties. [ABSTRACT FROM AUTHOR]

Molecule‐based magnetic materials are useful candidates as the spin qubit due to their long coherence time and high designability. The anisotropy of the g‐values of the metal complexes can be utilized to access the individual spin of the metal complexes, making it possible to achieve the scalable molecular spin qubit. For this goal, it is important to evaluate the effect of g‐value anisotropy on the magnetic relaxation behaviour. This study reports the slow magnetic relaxation behaviour of chromium nitride (CrN2+) porphyrinato complex (1), which is structurally and magnetically similar with the vanadyl (VO2+) porphyrinato complex (2) which is known as the excellent spin qubit. Detailed analyses for vibrational and dynamical magnetism of 1 and 2 revealed that g‐value anisotropy accelerates magnetic relaxations greater than the internal magnetic field from nuclear spin does. These results provide a design criterion for construction of multiple spin qubit based on g‐tensor engineering. [ABSTRACT FROM AUTHOR]

Molecule‐based magnetic materials are promising candidates for molecular spin qubits, which utilize spin relaxation behavior. Various kinds of transition metal complexes with S=1/2 have been reported to act as spin qubits with long spin‐spin relaxation times (T2). However, the spin qubit properties of low‐spin Ni(III) complexes are not as well known since Ni(III) compounds are often unstable. We report here the slow magnetic relaxation behavior and T2 values for three kinds of low‐spin Ni(III) based complexes with S=1/2 under magnetically diluted conditions. [Ni(cyclam)X2]Y (cyclam=1,4,8,11‐tetraazacyclotetradecane) with octahedral structures and [Ni(mnt)2]− (mnt=maleonitriledithiolate) with a square‐planar structure underwent slow magnetic relaxations in the presence of a dc magnetic bias field. From electron spin resonance (ESR) spectroscopy, the Ni(III) complexes exhibited observable T2, indicating that Ni(III) complexes are promising candidates for use as molecule‐based spin qubits. [ABSTRACT FROM AUTHOR]

Most of the information obtained by humans comes from colour images. However, salt‐and‐pepper noise (SPN) during signal acquisition, encoding, transmission, and decoding easily interferes with the quality of colour images. Most existing SPN denoising methods decompose a colour image into three independent matrices according to the colour channel and then recover each channel signal independently, ignoring the strong data correlation between channels. In addition, most existing SPN denoising methods apply only a single model‐driven or data‐driven approach and fail to take the advantages of their combination fully. Therefore, we first regard a colour image contaminated by SPN as the sum of an SPN tensor and a tensor with missing data. In this manner, we transform the denoising problem into a low‐rank tensor reconstruction problem. We then introduce a model‐driven‐based parallel matrix factorization low‐rank tensor reconstruction algorithm and a data‐driven‐based FFDNet denoising network to restore the colour image better. The proposed method not only enhances the similarity of the colour image channels but also explores the deep prior of the colour image to capture the image details. Finally, the proposed method is compared with some advanced denoising methods. The results show that the proposed method achieves a competitive denoising performance. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: Proton‐conductive metal‐organic frameworks (MOFs) have attracted great attention for their promising application in membrane fuel cells. To explore proton‐conductive MOFs with high performance, here we present four lanthanide‐hypophosphite frameworks with distinct amine guests. These complexes possess a general formula [AH][Gd2(H2PO2)7] (AH = protonated amines). Due to the rich hydrogen bond networks, complex 1 with guanidinium as guest shows high proton conductivity of 1.75 × 10–2 S·cm–1 at a relative humidity of 97% (368 K). We also studied the magnetic properties of complex 1 and reveal that the hypophosphite ligand transfers weak antiferromagnetic interactions between Gd3+ ions. [ABSTRACT FROM AUTHOR]

The reaction of Fe(OAc)2 and Hbpypz with neutral TCNQ results in the formation of [Fe2(bpypz)2(TCNQ)2](TCNQ)2 (1), in which Hbpypz=3,5‐bis(2‐pyridyl)pyrazole and TCNQ=7,7′,8,8′‐tetracyano‐p‐quinodimethane. Crystal packing of 1 with uncoordinated TCNQ and π–π stacking of bpypz− ligands produces an extended two‐dimensional supramolecular coordination assembly. Temperature dependence of the dc magnetic susceptibility and heat capacity measurements indicate that 1 undergoes an abrupt spin crossover (SCO) with thermal spin transition temperatures of 339 and 337 K for the heating and cooling modes, respectively, resulting in a thermal hysteresis of 2 K. Remarkably, the temperature dependence of dc electrical transport exhibits a transition that coincides with thermal SCO, demonstrating the thermally induced magnetic and electrical bistability of 1, strongly correlating magnetism with electrical conductivity. This outstanding feature leads to thermally induced simultaneous switching of magnetism and electrical conductivity and a magnetoresistance effect. [ABSTRACT FROM AUTHOR]

We report three self‐assembled iron complexes that comprised an anti‐parallel open form (o‐Lanti), a parallel open form (o‐Lsyn), and a closed form (c‐L) of diarylethene conformers. Under kinetic control, FeII2(o‐Lanti)3 was isolated, which exhibited a dinuclear structure with diamagnetic properties. Under light‐irradiation control, FeII2(c‐L)3 was prepared and exhibited paramagnetism and spin‐crossover behaviour. Under thermodynamic control and in the presence of indispensable [FeIII(Tp*)(CN)3]−, FeII2(o‐Lanti)3 and FeII2(c‐L)3 transformed into tetranuclear FeIII2FeII2(o‐Lsyn)2, which exhibited complete spin‐crossover behaviour at T1/2=353 K. That's so metal: By controlling the self‐assembly processes, three iron complexes composed of different diarylethene conformations were isolated. Importantly, this controlled self‐assembly also allowed the modulation of their magnetic properties. [ABSTRACT FROM AUTHOR]

Neuritin is a neurotrophic factor that is activated by neural activity and neurotrophins. Its major function is to promote neurite growth and branching; however, the underlying mechanisms are not fully understood. To address this issue, this study investigated the effects of neuritin on neurite and spine growth and intracellular Ca2+ concentration in rat cerebellar granule neurons (CGNs). Incubation of CGNs for 24 h with neuritin increased neurite length and spine density; this effect was mimicked by insulin and abolished by inhibiting insulin receptor (IR) or mitogen‐activated protein kinase kinase/extracellular signal‐regulated kinase (ERK) activity. Calcium imaging and western blot analysis revealed that neuritin enhanced the increase in intracellular Ca2+ level induced by high K+, and stimulated the cell surface expression of CaV1.2 and CaV1.3 α subunits of the L‐type calcium channel, which was suppressed by inhibition of IR or mitogen‐activated protein kinase kinase/ERK. Treatment with inhibitors of L‐type calcium channels, calmodulin, and calcineurin (CaN) abrogated the effects of neuritin on neurite length and spine density. A similar result was obtained by silencing nuclear factor of activated T cells c4, which is known to be activated by neuritin in CGNs. These results indicate that IR and ERK signaling as well as the Ca2+/CaN/nuclear factor of activated T cells c4 axis mediate the effects of neuritin on neurite and spine growth in CGNs. Open Practices: Open Science: This manuscript was awarded with the Open Materials Badge. For more information see: https://cos.io/our-services/open-science-badges/ Cover Image for this issue: doi: 10.1111/jnc.14195. Background: Neuritin could promote neurite growth and branching. In this study, we used cerebellar granule neurons (CGNs) to reveal the possible mechanism. Main findings and implication: Neuritin promoted neurite and spine growth by increasing Ca2+ influx through L‐type voltage‐gated calcium channel (L‐VGCC), which involves activation of the insulin receptor (IR)‐induced ERK signaling and Ca2+/ calcineurin/NFATc4 axis. Image content: Schematic illustration depicting the mechanisms of neuritin in the up‐regulation of the CaV1.2 and CaV1.3 subunits of L‐type VGCCs on the cell membrane, and the subsequent increase in neurite length, spine density, and KV4.2 expression. IRS: insulin receptor substrate. Cover Image for this issue: doi: 10.1111/jnc.14195. [ABSTRACT FROM AUTHOR]

Five lanthanide coordination clusters (CCs) [Ln7(µ3-OH)4(deg)2(Hdeg)2(ben)11]·xCH3CN [Ln = Eu (1), Gd (2), Tb (3), Dy (4), Ho (5); H2deg = diethylene glycol, Hben = benzoic acid; x = 7 for 1–4, x = 6 for 5], with diethylene glycol and benzoic acid as ligands, have been prepared and structurally characterized. All CCs consist of a heptanuclear lanthanide core with a scarce tip-sharing double-butterfly topology. Magnetic measurements revealed that CC 4 exhibits slow magnetic relaxation, with an energy barrier of about 6 K, whereas CC 3 shows outstanding magnetocaloric effects, with an entropy change of 34.6 J Kg–1 K–1 at 2 K and ΔH = 7 T. The photoluminescence properties of CCs 1, 3, and 4 were also investigated, displaying intense characteristic emission spectra of EuIII, TbIII, and DyIII ions. [ABSTRACT FROM AUTHOR]

A neutral mononuclear FeIII complex [FeIII(H-5-Br-thsa-Me)(5-Br-thsa-Me)]⋅H2O ( 1; H2-5-Br-thsa-Me=5-bromosalicylaldehyde methylthiosemicarbazone) was prepared that exhibited a three-step spin-crossover (SCO) with symmetry breaking and a 14 K hysteresis loop owing to strong cooperativity. Two ordered intermediate states of 1 were observed, 4HS-2LS and 2HS-4LS, which exhibited reentrant phase-transition behavior. This study provides a new platform for examining multistability in SCO complexes. [ABSTRACT FROM AUTHOR]

ABSTRACT Osteogenesis of mesenchymal stem cells (MSCs) is essential for bone repair. Recently, microRNAs have been proven to play an important role in the regulation of MSC differentiation, including osteogenesis. Here, the function of microRNA-21 (miR-21) in the osteogenic differentiation of human umbilical cord mesenchymal stem cells (hUMSCs) was investigated. Briefly, the miR-21 mimics (m-miR-21) and the antisense miR-21 (as-miR-21) were transfected to hUMSCs, and the capacity of miR-21 for the osteogenic differentiation of hUMSCs was evaluated by the expression of osteogenic markers encoding alkaline phosphatase (ALP), runt-related gene-2 (RUNX-2) and osteocalcin (OCN), as well as by Alizarin red S staining. The results indicated that the overexpression of miR-21 elevated the expression level of the osteogenesis-related genes of hUMSCs. During this process, the PI3K-AKT signaling pathway activity had an increasing tendency responding to miR-21 up-regulation. This enhancement promoted the phosphorylation of GSK-3β, leading to the stabilization and high concentration accumulation of β-catenin in cytoplasm to activate the transcription of RUNX-2, and finally increased the osteogenesis of hUMSCs. This work demonstrated that miR-21 and its target PI3K-AKT-GSK3β pathway played an important role in the osteogenic differentiation of hUMSCs by stabilizing β-catenin. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:957-964, 2015. [ABSTRACT FROM AUTHOR]

Spin doctor: A mononuclear ferric complex [Fe(H‐5‐Br‐thsa)(5‐Br‐thsa)]⋅H2O (1) (H2‐5‐Br‐thsa=5‐bromo‐2‐hydroxybenzylidene)hydrazinecarbothioamide) was synthesized and its magnetic properties and structure were investigated by DFT calculations. This complex shows unprecedented reversible, six/five‐step spin‐crossover behavior accompanied by symmetry breaking. More importantly, each step in the multi‐step transition was successfully characterized by single‐crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

B Thermally-induced simultaneous switching b of magnetism and electrical conductivity has been realized by a two-dimensional supramolecular coordination assembly composed of Fe SP II sp spin-crossover complexes and partially charged TCNQ (7,7',8,8'-tetracyano- I p i -quinodimethane) radicals. B Thermally-induced simultaneous switching b of magnetism and electrical conductivity has been realized by a two-dimensional supramolecular coordination assembly composed of Fe SP II sp spin-crossover complexes and partially charged TCNQ (7,7',8,8'-tetracyano- I p i -quinodimethane) radicals. Fe SP II sp spin-crossover units are directly linked to -stacked TCNQ columns, thus possessing strongly coupled magnetism (from localized d electrons) and electrical conductivity (from delocalized electrons). [Extracted from the article]

In the title compound, C12H6N2O2·C2H5OH, the mol-ecule of the 1,10-phenanthroline-5,6-dione is approximately planar, with a maximum deviation of 0.051 (1) Å. In the crystal, mol-ecules are linked by O-H⋯N and weak C-H⋯O hydrogen bonds, forming supra-molecular chains propagating along [110]. π-π stacking inter-actions are observed between the pyridine rings of neighbouring chains, the centroid-centroid separations being 3.6226 (11) and 3.7543 (11) Å.

In the title complex, [Fe(NCS)2(C18H18N4)], the Fe(II) cation is chelated by a tris-(2-pyridyl-meth-yl)amine ligand and coordin-ated by two thio-cyanate anions in a distorted N6 octa-hedral geometry. In the crystal, weak C-H⋯S hydrogen bonds and π-π stacking inter-actions between parallel pyridine rings of adjacent mol-ecules [centroid-centroid distance = 3.653 (3) Å] link the mol-ecules into a two-dimensional supra-molecular architecture. The structure contains voids of 124 (9) Å(3), which are free of solvent molecules.

In the title centrosymmetric dinuclear Eu(III) complex, [Eu(2)(CH(3)COO)(6)(C(12)H(8)N(2))(2)], each Eu(III) cation is coordinated by seven O atoms from five acetate anions and two N atoms from one phenanthroline ligand in a distorted tricapped trigonal-prismatic geometry. Four acetate anions bridge two Eu(III) cations to form the dinuclear complex, with an Eu⋯Eu distance of 3.9409 (8) Å. Weak inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

In the the title compound, C(19)H(18)BrNO(3), the furan-one ring is almost planar [maximum atomic deviation = 0.019 (3) Å] and is nearly perpendicular to the two phenyl rings, making dihedral angles of 88.96 (17) and 87.71 (17)°. Inter-molecular C-H⋯O hydrogen bonding is present in the crystal structure.

In the title compound, {[AgSm(C(6)H(4)NO(2))(2)(C(2)O(4))]·H(2)O}(n), the asymmetric unit contains one Sm(III) ion, one Ag(I) ion, two unique isonicotinate (ina) ligands, two half oxalate (ox) ligands (one on an inversion centre, the other on a twofold axis) and one uncoordinated water mol-ecule. The central Sm(III) ion is nine-coordinated by four O-donor atoms from separate bidentate bridging ox ligands and five O-donor atoms from the two ina ligands (both bidentate) and a symmetry-related ina ligand [Sm-O = 2.389 (4)-2.791 (4) Å], giving a distorted monocapped square anti-prismatic geometry. The Ag(I) ion is three-coordinated in a T-shaped geometry involving two ina N-donor atoms [Ag-N = 2.181 (6) and 2.185 (5) Å] and a bridging oxalate O-donor atom [Ag-O = 2.620 (4) Å]. The three-dimensional heterometallic Sm-Ag coordination polymer, having a unique (3,4,6)-connected five-nodal net topology, is constructed from two-dimensional samarium-oxalate layers and pillared Ag(ina)(2) subunits. Inter-molecular water-carboxyl-ate O-H⋯O hydrogen-bonding inter-actions are also present.

The title compound, C(19)H(30)BrNO(5), was obtained via a tandem asymmetric Michael addition-elimination reaction of 3,4-dibromo-5-[(S)-l-menth-yloxy]furan-2(5H)-one and l-valine in the presence of potassium hydroxide. The mol-ecular structure contains an approximately planar (r.m.s. deviation = 0.0204 Å) five-membered furan-one ring and a six-membered menth-yloxy ring adopting a chair conformation. The crystal packing is stabilized by inter-molecular O-H⋯O and N-H⋯O hydrogen bonding.

The title compound, C(19)H(30)ClNO(5), was obtained by the tandem asymmetric Michael addition-elimination reaction of (5S)-3,4-dichloro-5-(l-menth-yloxy)furan-2(5H)-one and l-valine in the presence of potassium hydroxide. The furan-one unit is approximately planar (r.m.s. deviation = 0.0204 Å) and the six-membered cyclo-hexane ring adopts a chair conformation. The crystal structure is stabilized by a network of O-H⋯O and N-H⋯O hydrogen bonds.

The three-dimensional polymeric title compound, {[Zn(C(9)H(4)N(2)O(4))]·H(2)O}(n), contains one crystallographically independent Zn(II) atom, one fully deprotonated 1H-benzimid-azole-5,6-dicarboxyl-ate (bdc) ligand and one uncoordinated water mol-ecule. The Zn(II) atom is four-coordinated by three O atoms and one N atom from the bdc ligands, giving a distorted tetra-hedral coordination geometry. The uncoordinated water mol-ecule is bound to the main structure through a strong bdc-water N-H⋯O hydrogen bond, and two much weaker water-bdc O-H⋯O inter-actions.

The title compound, C(17)H(26)ClNO(5), was prepared via a tandem asymmetric Michael addition-elimination reaction of (5S)-3,4-dichloro-5-(l-menth-yloxy)furan-2(5H)--one and l-alanine in the presence of potassium hydroxide. The five-membered furan-one ring is approximately planar while the six-membered menth-yloxy ring adopts a chair conformation. The crystal packing is stabilized by inter-molecular O-H⋯O and N-H⋯O hydrogen bonds.

In the title compound, C(11)H(12)ClN(5)O, the triazolone and pyrimidine rings are almost coplanar [dihedral angle = 2.98 (14)°]. The total puckering amplitude Q(T) of the seven-membered lactam ring is 0.706 (3) Å.